animate-elem-81-t

This test validates the operation of the animateTransform's
additive behavior, as described in the SVG 1.1 specification
(see
http://www.w3.org/TR/SVG11/animate.html#AnimateTransformElement).

The first two rectangles, on the top row, show the effect of the
additive attribute on animateTransform. The left-most
animateTransforms have their additive attribute set to replace,
so the effect of the two transform animation is as if only the
highest priority one applied because it replaces the underlying
value. The second animateTransforms (from left to right) have
their additive attribute set to sum, which means the transforms
they produce are concatenated.

The last two rectangles, on the top row, show the effect of the
accumulate attribute on animateTransform. For the left one
(third on the row, from left to right), the accumulate attribute
is set to none. There are two repeats for the
animateTransform. Therefore, the transform goes twice from a
scale(1,1) to a scale(2,2). For the right-most animateTransform,
the accumulate attribute is set to sum. There are two repeats
and the animation goes from scale(1,1) to scale(2,2) for the
first iteration and then from scale(2,2) to scale(4,4) (because
the result of the second iteration is concatenated to the
scale(2,2) result of the previous, first iteration).

The rectangles on the bottom row show the combination of
additive and cumulative behavior. The left rectangle's
animateTransform accumulate behavior is set to none but its
additive behavior is set to sum. Therefore, the transform's
underlying value (skewX(30)) is always pre-concatenated to the
animateTransform's result, which goes from "skewX(30)
scale(1,1)" to "skewX(30) scale(2,2)" in each of its two
iterations. The right rectangle's animateTransform accumulate
behavior is set to sum and the additive behavior is also set to
sum. Therefore, the transform's underlying value is always
pre-concatenated, so is the result of previous animation
iterations. Consequently, the transform goes from "skewX(30)
scale(1,1)" to "skewX(30) scale(2,2)" for the first iteration
and then from "skewX(30) scale(2,2) scale(1,1)" to "skewX(30)
scale(2,2) scale(2,2)" for the second iteration.